Ball pusher for grinding mills



, 1.. L. LLEACH 1,975,514

BALL PUSHER FOR GRINDING MILLS Oct. 2, 1934.

Original Filed March 8, 1928 millllllllllfi m M lNVENTOR J1 w I M TTORNEY- Patented Oct. 2, 1934 UNITED STATES BALL PUSHER Foa GRINDING MILLS Lester L. Leach, New York, N. Y., assignor to Fuller Lehigh Company, Fullerton, Pa., a corporation of Delaware Application March 8, 1928, Serial No. 259,970 Renewed September 17, 1932 9 Claims.

This invention relates to a device for pushing the grinding balls along the grinding surface of the grinding ring of a mill of the well known type. I-Ieretofo-re pushers of this sort have been made in such a manner that when the portions thereof which contact with the balls become worn, it is necessary to throw away a large amount of metal in order to replace the Worn parts. Another difficulty has been that when the pusher wears away to a certain extent, the grinding balls which have been worn so as to be of barrel shape are apt to become caught in the worn spots and cease to turn so that the balls no longer roll over and grind the ma- 1'5j terial that is to be ground but simply slide along the grinding surfaces.

By the present invention these difiiculties are overcome and a pusher is made in such a manner that it can be repaired very much more easily and economically than heretofore after it has become worn. In carrying out the invention, the arms of the pusher are provided with holes or sockets into which pusher pins may be inserted and withdrawn whenever desired. The front ends of the pusher pins or the portions that contact with the balls are made of such shapes that the balls are caused to wear uniformly and maintain their spherical shapes, and the ends are made of hardened material so as to minimize the wear. When the parts that contact with the balls are worn, they can be taken out and new ones can be readily inserted in their places without the loss of any considerable amount of metal.

The invention will be understood from the description in connection with the accompanying drawing in which Fig. 1 is a plan view of the device; Fig. 2 is a section along the line 22 of Fig. 1, and Fig. 3 is a section through the pin along the line 33 of Fig. 1.

In the drawing reference character 1 indicates a grinding ring of a ball mill of a well known type in which the grinding balls are indicated by the reference character 2. The yoke 3 of the ball pusher is provided with arms 4 and transverse tapered openings 5 are provided near the outer ends of the arms 4. Each arm 4. is provided with a lug or extension 6 near the opening 5 for a purpose to be described hereinafter, and the front side of each arm 4 is provided with a fiat face or seat 7 for a portion of the pusher pins.

Each pusher pin comprises a tapered shank 8 to fit into the tapered hole 5 and a head 9 that extends forwardly beyond the flat face or seat 7 on the forward edge of the corresponding arm 4. A ring 10 is provided around each pin at the-end of the shank 8 and has a notch or recess 11 across the same into which the corresponding lug 6 on the arm 4 fits to prevent the a l pin from turning when it is in place. The outer lower edge of the head 9 of each pin is provided with an extension 12 and the front end or face of the pin may be provided with hardened material 13 to resist wear. The extensions 12 along 5 the outer lower portions of the pins will cause the balls to be moved inward towards the center of the mill and jump over any obstruction, such as a piece of metal or the like, that may accidentally get into the mill. These extensions '10. 12 also make contact with the balls at such points that the balls will not rotate about vertical axes. On the contrary, the balls will rotate about different axes and thus the tendency of the ball to wear barrel-shaped is overcome. The positions of the pusher pins are such and their front ends are so shaped that the contact points between the pins and the balls are slightly below the horizontal center line of the balls and the perpendicular distance from the point of contact be- 30, tween a pin and ball to the grinding surface of the grinding ring is approximately equal to the radius of the ball.

I claim:

1. In a grinding mill, grinding balls, a ball 5, pusher having arms with openings near the ends thereof, pusher pins extending into said openings, and each pin having a ring with a notch in it and lugs on said arms extending into said notches.

2. In a grinding mill, grinding balls, 2. ball pusher having arms with openings near the ends thereof, and pusher pins in said openings, each pin having an extension along its outer lower edge at its front end.

3. In a grinding mill, grinding balls, pushers for said balls, said pushers being constructed and arranged to contact with said balls only at points at a lower level than the centers of said balls and approximately as far away from the grinding surface as the centers of said balls.

4. In a grinding mill, grinding balls, pushers for said balls, and means comprising pins with sloping faces mounted on said pushers to contact with said balls only at points below the center line of said balls and cause said balls to revolve about a nonvertical axis.

5. In a grinding mill, grinding balls, a ball pusher having arms with tapered openings, the large end of each opening being adjacent the 1.

ball, removable pusher pins having tapered shanks extending into said openings whereby the pins are held in place by the pressure of the balls, means on said pins spaced forwardly from the arms and contacting with said balls, and cooperating means on said arms and on the pins exteriorof said openings to prevent rotation of the pins in the openings.

6. In a grinding mill, grinding balls, pushers for said balls, means comprising pins with sloping faces mounted on said pushers to contact with said balls only at points below the center line of said balls and cause said balls to revolve about a nonvertical axis, said pins having tapered shanks extending into tapered openings in said pushers, and means on the pins exterior of said openings and on the pushers to prevent rotation of the pins in the openings.

7. In a grinding mill, grinding balls, a grinding ring for said balls, pushers for said balls, and means comprising pins mounted on said pushers contacting with said balls to push them around said ring, said pushers contacting with said balls only at points lower than the centers of said balls to cause said balls to wear substantially uniformly.

8. As an article of manufacture, a grinding mill ball pusher pin having a shank, an intermediate enlarged ring portion, and a driving head portion at the side of said ring opposite said shank, said. driving head having a sloping face terminating at its forward end in the lower outer portion of said driving head.

9. In a grinding mill, grinding balls, a grinding ring for said balls, means for moving said balls Within said grinding ring comprising radial- 1y extending arms and pusher pins removably mounted in said arms, each of said pins having a driving head with an outwardly sloping ballcontacting face at its forward end contacting with a corresponding ball at a point below and outside the center of the driven ball.

LESTER L. LEACH. 

